1. Field of the Invention
This invention relates to an orientation detector of sources emitting radioactive radiation.
2. Background of the Prior Art
Wilcox U.S. Pat. No. 3,436,539 describes a detector of the azimuth angle of the source (the angle formed by the direction of the source with a fixed vertical plane). The Wilcox detector comprises three crystals located in a box or case at angular intervals of 120.degree.. The crystals are partly inserted in a screen, which has partial absorption properties of the radiation as a function of the distance by which said radiation traverses said material. For certain orientations of the source, a crystal is directly reached by the radiation and the two other crystals are reached after the radiation has traversed a certain screen thickness. For other source orientations, the three crystals are only reached after the radiation has traversed part of the screen. As a function of the azimuth of the source, it is possible to obtain signals from the crystals having a sinusoidal configuration and phases displaced by 120.degree., but this leads to a very complicated shape of the screen.
The Wilcox invention relates to a detector comprising a screen partly absorbing the radiation and sensors located in said screen, but the detector described hereinafter has a much simpler design and is able to supply more precise and more complete measurements. Moreover, unlike other detectors, there is no need to orient it towards the source in order to carry out the measurement.